1) Ballad singer 2) Balladeer 3) Bing Crosby 4) Bing Crosby or Rudy Vallee 5) Bing crosby, famously 6) Bublé or Sinatra 7) Columbo or Vallee 8) Como or Crosby, notably 9) Crosby or Columbo 10) Crosby, notably 11) Mellow country music artist 12) Pop singer 13) Robert Goulet 14) Silky-voiced singer 15) Sinatra 1) Balladeer 2) Crosby 3) Sinatra 4) Singer 5) Thrush 
Crooner is an American epithet given to male singers of jazz standards, mostly from the Great American Songbook, either backed by a full orchestra, a big band or by a piano. Originally it was an ironic term denoting an emphatically sentimental, often emotional singing style made possible by the use of microphones. Some performers, such as Russ Col...
[n] - a singer of popular ballads
balladeer noun a singer of popular ballads